Microbial strain with good quality is the center of bio-industry, and how to effectively utilize biological mutagenesis technique to achieve rapid microbial strain optimization is an important task for biological industry. Conventional biological mutagenesis methods normally have disadvantages of low efficiency, heavy workload, and low specificity, etc.; chemical mutagenesis also tends to cause injuries to the operation staff, bring contamination to the environment; and physical mutagenesis has poor mutagenesis capability and the microorganism employed will display resistance after reuse; also, other methods often require professional and complicated devices, and some of them cost very high. Therefore, conventional biological mutagenesis methods are not suitable for the development of industrial bacterial strains, and a new, highly effective mutation breeding technique which can be operated easily, increase the efficiency and shorten the screen cycle of the mutation breeding is in demand.